Fluid pressure pump



March 21, 1933. w, VALENTINE 1,902,345

FLUID PRESSURE PUMP Filed April 2, 1951 2 Sheets-Sheet l Y W l 9 31 Kg J A ind March 21, 1933.

W. F". VALENTINE FLUID PRESSURE PUMP 2 Sheets$heet '2 Filed April 2, 1931 Patented Mar. 21, 1933 UNITED sTATEs PATENT OFFICE WARREN P. VALENTINE, or LINE LEXINGTON, 'rENNsyLv NIA, ASSIGNOR T0 NATIONAL TRANSIT PUMP & MACHINE COMPANY, or OIL CITY, PENNSYLVANIA, I;

A. CORPORATION OF PENNSYLVANIA FLUID PRESSURE PUMP Application filed April 2, 1931. Serial No. 527,068.

eating the plungersonce each revolution of the pump and the circumferential casing of the pump presenting passages angularly located to respectively register with the outer endsof the cylinders during the outward, and inward movements of the plungers.

A purpose of my invention is to increase the length of the circumferential seal between the inlet and outlet passages of a pump of the character indicated inorder to permit wear'and erosion of the sealing surfaces without materially changing the effective operation of the pump, even when through long continued service such wear and erosion has materially lessened the lengths of seal and would have rendered -in-- operative the pumps of the prior art.

A further purpose is to allow for outward movements of the plungers of pumps of the character indicated during the passage of the outer ends of the plunger cylinders across a relatively long end seal by pro viding forwardly extending pressure relief passages. if

A further purposeis to provide each cylinder of a pump of the character indicated with a relief passage extending through the cylinder block forward of the cylinder in the direction of relative movement of the cylinder block and casing. V

A further purpose is to provide a pump of the character indicated, which has a link connection between the crank and one of the plungers and which is enlarged to form wrist plate about the crank to operate the remaining plungers, with novel construction that reduces the requisite distance between' the crank and the plungers and thereby the requisite diametral size to the rotor.

A further purpose is to-provide an advantageous and novel pump structure which operates effectively on viscous oils and stiif greases and 1s easily and 1nexpenslvely circumferentially spaced inwardly open inlet and discharge volved.

manufactured and of service. i V V A further purpose is to construct a rotary pump well suited to use as a gauge.

Further purposeswill appear in the speci- 5 well suited to the-needs fication and in the claims. V

I have elected to show one form only of my invention, selecting a form that ispractical and eflicient in operation and which well illustrates the principles in- Figure l is a transverse section through cylinder block and casing structure that embodies one form of myinvention. v

Figure 2 is a section of Figure 1 taken upon the line 22 thereof.

Figure 3 is a view corresponding generally to Figure 1, except that the parts are further advanced, the cylinder block in F igure'3 being advanced beyond its posi tion in Figure l. p

Figure 4 is an elevation, in part section upon the line 44 of Figure Like numerals refer' to like parts ina'll figures. c f 75 Describing in illustration and not in limitation and referring tothe drawings In rotary pumps of this a character, in which a cylinder block having radial cylinders equipped with radially reciprocating 30 plungers moves with respect to a casing, the question as to whether the casing is stationary and the cylinder block turns or the cylinder block is stationary and the cas ing turns is of relatively little importance, since in any case :there will berelative Qrotation of the cylinder block with respect to-the casing. In the form illustrated, the cylinder block is intended to turn, and therefore tobe a rotor, is merely my preferred construction.

The rotor includes a'shaft 5 rotated in any suitable way not shown, and a hollow cylinder block 6 carried uponthe shaft, the cylinderblock being radially bored to form cylinders at 7, 8, 9 and 10 and the block interior providing space for mechanism reciprocating the plungers 11,12, 13 and 14in on v ward end a flange 16 forming the inner end casing of the cylinderblock and supporting the circumferential casing 17 and forward or outer end casing 18.

On the end casing 18, supporting lugs 19 adjustably position a sliding plate 20 by means of adjusting screws 21. The plate 20 is movable longitudinally in a guideway 22. The plate 20 carries an inwardly directed crank pin 23 that is parallel to the shaft of the rotor and laterally spaced therefrom at a distance selected to give the desired range of movement to the plungers 11, 12, 13 and 14.

The crank pin 23 is desirably adjustable in its distance from the axis of the shaft 5, as through shifting the settings of the adjusting screws 21. Obviously changing the position of the plate 20-adjustably changes the throw of the'plungers and thereby changes delivery of the pump when operated at a given speed. i s c A wrist plate 24 pivotally mounted. on the crank pin 23 has operative connections with the individual plungers, one of these connections 25 comprising an arm pivoted at its outer end to the plunger 11 and at its inner end desirably integral with the wrist plate.

The other connections include links 26, 27 and 28 which are pivoted to the wrist plate at one end and to the plungers 12, 13

and 14: respectively at the other end.

The'wrist plate is recessed at 29 to receive the inner ends of the links 26, 27 and 28, these ends being connected by the screw pivots 30 to the spaced plate portions 31 of the wrist plate.

For ease of assembly and manufacture, the cylinder block is transversely divided at 32 in a plane which longitudinally bisects the radial cylinders 7, 8, 9 and 10 carrying the plungers. The end casing 18 is annularly recessed at 33 to fit the outer end of the cylinder block, the annular recess, being shown deepened somewhat at 34 throughout itslength to provide an oil groove.

' The circumferential casing 17 presents in wardly open inlet and discharge passages 35 and 36 respectively to circumferential portions of the cylinder block, these passages being located on opposite sides of a diametral line 37 through the cylinder block and crank axes, with ,arcuate circumferential sealing portions 38 and 39 intermediate and adjacent ends ,of the passages.

It will be understood that the open ends of the cylinders 7, 8, 9 and 10 successively register with the inlet passage 35 during the periods of radial inward plunger travel and register with the outlet passage during the periods of radial outward plunger travel. For counterclockwise cylinder block rotation as contemplated inthe form shown, the

lun ers ass from inward to outward travel somewhere along theseal 38 and from outthe seal 39 and their extreme inward positions at the seal 38.

But for the fact that the wrist plate arm 25 itself is angularly changing position and thus changing the angular setting of the wristplate supports for the links, the pistons 12 and let when in the position of Figure 3 would have their maximum inner and outer strokes in angular positions corresponding with the'line 37. Because of the angular displacement (as guided by the arm 25) this is altered, so-that theangular positions of maximum inward and outward movements are changed to correspond with some such lines as 40 and 41.

While the pistons are angularly close to the dead center lines, their actual longitudinal movements are relatively small, and an important feature of the-present invention incudes the provision of long seals at 38 and 39, extending a considerable distance beyond the dead center lines with forwardly extending relief ports 42 in the different cylinders positioned to permit small outward movements of the plungers while the outer ends of the cylinders carrying the plungers are passing the long seal 38.

The .relief ports 12 do not function at the seal 39, since the plungers are there in their outermost positions, and subsequently will move inwardly.

The widest application of the invention is thought to be in 'piunping greases and heavy liquids, both of which are incompressible and therefore readily block any substantial outward movements of the plungers if sealed within the spaces ahead 7 of the plungers, and because of this fact, inventors and othershave in the past provided seals at 38 that are relatively quite short as compared with the length of seal used by the applicant.

Small inward movements of the plungers when passing the seal 39 result in a suction resistance to the rotor movement that is of merely minor importance since it is relatively low, being limited to that needed to overcome atmospheric pressure.

In the past the sealing surfaces between the inlet and discharge passages 35 and 36 of pumps of the typeunder consideration have become worn oreroded in use to such an extent as to destroy the effectiveness of the pump long before any accompanying deterioration of the mechanism has become material. Wear has been most pronounced in pumping heavy liquids,-; such. as cup grease and other lubricants of high viscosity. The erosion and wear usually take place from the rearwardly directed surfaces l3 and 44:, for example, as indicated by the dotted lines 45 and 46, and the long sealing surfaces of the present invention permit wear without loss of seal betweenthe inlet and outlet passages. r

The pressure relief passages 42, extending forward perpendicular to the cylinderaxes from intermediate points of the cylinders "7, 8, 9 and 10 to the outside circumference of the cylinder block permit the'rather' small outward movements of the plungers when passingthe long seal 38, since without these relief passages the incompressible fluid filling the cylinders whilethe cylinders are closed by the seal 38 would block the'plungers from moving outward. 7 As a result ofthe relief passages 42, the plungers can thus move outwardly whilethe outer ends of the cylinders are sealed,"be-

cause the outward displacements vof the plungers is accommodated by corresponding discharge of the grease or other fluid within the cylinders through the relief passages 42 to thedischarge passage36.;

The corresponding inward movements of the plungers while passing the seal 39'meets a mere suction resistance that cannot exceed a relatively small value, too small to give material-trouble.

Another important feature of the inven-' ferences in the radial distances of the pistons from the crank when the pistons respectively reach the same position. By

using a yoke form of wrist plate, I am enabled to support both ends of the link pins, thus distributing the load between the ends of the pins. 7

My form of pump is particularly well suited for use as a gauge, since its discharges measured quantities from the cylinders and is not subject to inaccuracy due to destruction of the circumferential seal by wear. When the pump is employed as a gauge I will drive either the cylinder block or the casing, and not rely on the liquid to operate the rotor.

In View of my invention and disclosure, variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such in so far as they fall withinthe reasonable spirit and scope of my invention.

Having thusdescribed my invention, what'- I cla m as new and desire to secure by Letters Patent is 1. A pump of the character indicated eomprising a cylindrical rotor having a hollow recess extendii'ig rearwardly-fromits forward end and having circumterentially spaced radial bores intersecting said recess,

a plunger in each bore, a stationary eccen:

trio pin, an operating connection between said pin and'said plungers whereby rotation of the rotor reciprocates the plungers in tively of the plungers within the bores and seals comprising casing portions making arcuate sealing engagements with the outs1de of the rotor lntermediate the passages at positions to respectively register the? seals with the bores when the plungers therein are at their innermost and oute'rmost'positions, and the seal in position to register with the bores while the plungers thereof are at their innermost positions having an arcuate forward sealing extension sealing the open ends of the bores during early portions of the outward movements of the plungers within the bores, said rotor having a perforation extending forwardly from an intermediate point only of each bore to a point on the circumference of the rotor such that the bore is-conneeted to the discharge passage through the perforation while the open end of the bore isclosed by the sealing extension and the perforation is sealed when the piston extends outwardly beyond the intermediate point.

2. 'A pump of the character indicated, comprising acylindrical rotorhaving a hollow recess extending rearwardly from its forward end and having circumferentially spaced radial bores intersecting said recess, a plunger in each bore, a stationary eccentric pin,"an operating connection between said pin and said plungers Where by'rotation of the rotor reciprocates the plungers in their respective bores, an external casing presentinga surface toward the rotor recessed outwardly to provide inlet and outlet passages respectively registering with the ends of the bores during major portions of the inward and outward movements respectively of the plungers within the bores and seals comprising casing portions making arcuate sealing engagements with the outside of the rotor intermediate the passages at positions torespectively register the seals with the bores when the plungers therein are at their innermost and outermost positions, and the seal in position to register with the bores while the plungers thereof are at their innermost posirelativelv reciorocatin lun ers inlet and l a z; 7

outlet tompartments with which the cylinders communicate and opposite sealing arcs of engagements separating the compartments, the art which consists in circumferentially extending the sealing engagements greatly in excess of the circumferential spans of the plungers and in by-passing the discharge. from points short of the ends of the cylinders to permit outward movements of the plungers during parts of the successive sealing engagements and providing for sealing the discharges by the pistons in the outer partsof the piston movements.

4. In a rotary pump of the character indicated, comprising a casing and a cylinder block containing pump cylinders with their relatively reciprocating plungers, inlet and outlet compartments with which the cylinders communicate and opposite sealing arcs of engagements separating the compartments, the art which consists in discharging fluid from the cylinders in turn ahead of each of the pistons into the outlet compartment before the outer cylinder openings in their circumferential movement have reached the compartment and in sealing the discharge from the cylinders while the pistons are in the outer parts of their strokes.

5. A rotary pump of the character indicated, comprising an outer casing having inlet and outlet connections and compartments, a cylinder block therein relatively r0- tatable with respect to the casing, walls forming cylinders in the block in spaced positions about the block, sealed against the casing at opposite sides during movement over an angular distance greater than the circumferential spread of each cylinder, pistons in the cylinders, a crank revoluble with respect to the cylinder block, connections from the crank to the respective pistons and walls forming by-passes-from intermediate points in the cylinders to theoutlet compartment in advance of other connections of the cylinders therewith in the direction of relative block rotation, whereby thecylinders before the ends of the cylinders are connected with the outlet compartment and the by-passes are closed by the pistons in outer parts of the piston strokes.

6. A rotary pump of the character indicated, comprising an outer casing having inlet and outlet connections and compartments, a cylinder block therein relatively rotatable with respect to the casing, walls forming cylinders in the block in spaced positions about the block, sealed against the casing at opposite sides during movement over an angular distance greater than the circumferential spread of each cylinder, pistonsin the cylinders, a crank revoluble with respect to the cylinder block, connections from the crank to the respective pistons, walls forming by-passes from intermediate points in the cylinders to the outlet compartment in advance, in thedirection of relative block rotation, of cylinder connection therewith, each by-pass being sealed at all times by the piston of its cylinder during its connection with the inlet compartment except when its. cylinder end is connected with said inlet compartment.

WARREN P. VALENTINE.

may discharge to the outlet compartment 

